Although I hadn't heard of Stefan Brands before, I wasn't surprised he'd worked with David Chaum, who is the person I first think of regarding zero-knowledge proofs: http://sceweb.sce.uhcl.edu/yang/teaching/csci5234WebSecurity...
Then I get depressed because we had anonymous digital cash 20 YEARS AGO and fucked it up.
Software patents are bad, crypto patents are worse. It's (almost) literally patenting math.